3D Bioplotter Research Papers

Osteochondral repair remains a significant clinical challenge due to the multiple tissue phenotypes and complex biochemical milieu in the osteochondral unit. To repair osteochondral defects, it is necessary to mimic the gradation between bone and cartilage, which requires spatial patterning of multiple tissue-specific cues. To address this need, we have developed a facile system for the conjugation and patterning of tissue-specific peptides by melt extrusion of peptide-functionalized poly(ε-caprolactone) (PCL). In this study, alkyne-terminated PCL was conjugated to tissue-specific peptides via a mild, aqueous, and Ru(II)-catalyzed click reaction. The PCL-peptide composites were then 3D printed by multimaterial segmented printing to generate…

In this work, we describe a new 3D printing methodology for the fabrication of multimaterial scaffolds involving the combination of thermoplastic extrusion and low temperature extrusion of bioinks. A fiber engraving technique was used to create a groove on the surface of a thermoplastic printed fiber using a commercial 3D printer and a low viscosity bioink was deposited into this groove. In contrast to traditional extrusion bioinks that rely on increased viscosity to prevent lateral spreading, this groove creates a defined space for bioink deposition. By physically constraining bioink spreading, a broader range of viscosities can be used. As proof-of-concept,…

In this study of three-dimensional (3D) printed composite β-tricalcium phosphate (β-TCP)-/hydroxyapatite/poly(ɛ-caprolactone)-based constructs, the effects of vertical compositional ceramic gradients and architectural porosity gradients on the osteogenic differentiation of rabbit bone marrow-derived mesenchymal stem cells (MSCs) were investigated. Specifically, three different concentrations of β-TCP (0, 10, and 20 wt%) and three different porosities (33% ± 4%, 50% ± 4%, and 65% ± 3%) were examined to elucidate the contributions of chemical and physical gradients on the biochemical behavior of MSCs and the mineralized matrix production within a 3D culture system. By delaminating the constructs at the gradient transition point, the spatial separation of cellular phenotypes could be specifically…

Recent developments in 3D printing (3DP) research have led to a variety of scaffold designs and techniques for osteochondral tissue engineering; however, the simultaneous incorporation of multiple types of gradients within the same construct remains a challenge. Herein, we describe the fabrication and mechanical characterization of porous poly(ε-caprolactone) (PCL) and PCL-hydroxyapatite (HA) scaffolds with incorporated vertical porosity and ceramic content gradients via a multimaterial extrusion 3DP system. Scaffolds of 0 wt% HA (PCL), 15 wt% HA (HA15), or 30 wt% HA (HA30) were fabricated with uniform composition and porosity (using 0.2 mm, 0.5 mm, or 0.9 mm on-center fiber spacing), uniform composition and gradient porosity, and…

In this work, we present a printing method to fabricate scaffolds consisting of multimaterial segmented fibers. Particularly, we developed a reproducible printing process to create single fibers with multiple discrete compositions and control over the distribution of particulate ceramics—namely hydroxyapatite (HA) and β-tricalcium phosphate (TCP)—within poly(ɛ-caprolactone)-based composite scaffolds. Tensile testing revealed that the mechanical integrity of individual segmented fibers was preserved compared with nonsegmented fibers, and microcomputed tomography and thermal analysis confirmed the homogeneous distribution of ceramics incorporated in the fiber compositions. Moreover, we printed and characterized composite scaffolds containing model inverse radial gradients of HA and TCP that could…